Dental or orthodontic appliances such as braces are known for correcting tooth alignment. These appliances are, however, regarded by many patients, especially adults, as unsightly.
A known alternative to braces comes in the form of a removable appliance which, in the general fashion of a mouthguard, is received over an arch of teeth of a patient. An appliance of the type in question is at least partially elastically deformable, being constructed to be elastically deformed when received over an arch of teeth including a misaligned tooth or teeth, so that, by virtue of the elastic deformation, the appliance applies correction forces on a misaligned tooth or teeth. These type of appliances are of transparent construction, so that they have little or no obvious adverse aesthetic effects on the appearance of a patient.
However, because of the material from which these appliances are constructed, corrective movement of a tooth by a single appliance is limited, so that a great number of sequential appliances (e.g. 40) are required to correct tooth alignment, especially in cases where significant alignment correction is required. Another disadvantage of these type of appliances is that their construction is of such a nature that they do not naturally properly seat on an arch of teeth. When an appliance in question is forced to seat properly on an arch of teeth, it, on the one hand, may lead to damage of the appliance and, on the other hand, may cause discomfort to a patient and/or cause tissue and/or tooth damage. For example, excessive force applied to a tooth by means of an appliance in question may result in root resorption or, in some cases, may restrict blood supply to the tooth, which adversely affects the vitality of the tooth with consequential discoloration of the tooth.